It has always been an interesting topic for people to exploring usages of specific wavelength of light. For example, the light can show different colors because of different wavelengths of light, and the light can be directly used as indicator tools in our social life. Certainly, the light having specific wavelength can be applied to many more fields. The light having specific wavelength can be applied to control switching device. Specifically, a fluorescence spectrometer is connected to a switch; a specific laser is used to stimulate fluorescence; the fluorescence spectrometer is used to measure the fluorescence wavelength and transmit the fluorescence wavelength to the switching device to turn on the switching device. However, the fluorescence spectrometer costs very much and it's structure is very complex.
What is needed, therefore, is to provide an optical switching device for solving the problem discussed above.